1. Field of the Invention
The invention relates to a method for machining a cylinder head comprising a cooling jacket, with the fire deck of the cylinder head which is in a raw state being machined by material removal in relation to a reference mark of the cylinder head. The invention further relates to a cylinder block for a liquid-cooled internal combustion engine with a cylinder or a group of cylinders which consist of several cylinders Which are cast together, comprising a liquid compartment which encloses the cylinder or group of cylinders and which is enclosed by an outside wall, with gaps being provided between the cylinder or the outer cylinders of the group of cylinders and the outside wall of the cylinder block through which the cooling liquid flows from one side to the other side of the cylinder or the group of cylinders, with at least one plug which reduces the cross section being arranged in at least one gap.
2. The Prior Art
In order to fulfill predefined tolerance requirements for the wall thickness between fire deck and cooling jacket, machining by material removal of the fire deck of a cylinder head is necessary. It is known to use sprue cut-offs in the gas exchange ports in the region of the valve guide cut-offs as reference marks for machining by material removal. This leads to the disadvantage however that relatively large tolerances need to be taken into account for the wall thickness of the fire deck in the region of the valve reinforcing ribs on the exhaust side. In the most extreme of cases, this may lead to insufficient cooling of the valve reinforcing ribs on the exhaust side.
A cylinder block is known from DE 198 40 379 A1 in whose cooling liquid chamber a plug which reduces the flow cross section is arranged in the region of a gap between an outer cylinder and the outside wall of the cylinder block. A defined minimum quantity of cooling fluid is able to pass the plug via cooling-fluid passages.
It is the object of the invention to avoid this disadvantage and to ensure sufficient cooling, especially the valve reinforcing ribs on the exhaust side. It is a further object of the invention to enable a purposeful control of the coolant flow in the cylinder block.